Configuration of 4 switches for aggregation

To configure four aggregation switches, use consistent port settings, choose LACP or static aggregation, and consider MC-LAG for redundancy and load balancing.

Step 1: Plan Your Aggregation Topology

Before configuration, map out which switches will be aggregated and how traffic will flow. Decide whether you will use static aggregation (manual configuration) or LACP (dynamic negotiation) for each link. For higher resilience, consider MC-LAG, which allows two switches to act as a single logical unit, providing redundancy and load balancing across multiple switches .

Step 2: Ensure Consistent Port Settings

All ports in an aggregation group must have consistent attributes:

• STP settings: enable/disable, priority, and cost
• VLAN configuration: permitted VLANs and PVID
• Port attributes: speed, duplex (full duplex required), and link type (trunk, hybrid, or access),

Step 3: Configure Aggregation Groups

1. Enable privileged or global configuration mode on each switch.
2. Create aggregation groups:
   • Static mode (ON): ports are manually added; LACP is not required.
   • LACP Active mode: ports initiate LACP negotiation.
   • LACP Passive mode: ports respond to LACP negotiation .
3. Assign a channel group ID to each aggregation group. Ensure no port is assigned to multiple groups .

Step 4: Configure Load Balancing

Select a load balance policy (e.g., source MAC, destination MAC, or IP-based) to distribute traffic across aggregated links. This ensures optimal utilization of all physical links in the group .

Step 5: Configure MC-LAG (Optional for Redundancy)

If using MC-LAG:

• Pair two switches as a logical unit.
• Connect downstream switches or servers to both MC-LAG switches.
• Ensure LACP or static aggregation is configured consistently on both MC-LAG peers .

Step 6: Verify and Test

• Check that all aggregated ports are up and synchronized.
• Use switch management tools (e.g., UniFi Controller) to monitor traffic distribution and failover.
• Test redundancy by disconnecting a link and confirming traffic continues on remaining links .

Step 7: Documentation and Maintenance

• Document aggregation group IDs, port assignments, and load balancing policies.
• Periodically verify configuration consistency and update firmware to maintain stability. By following these steps, your four aggregation switches will provide increased bandwidth, redundancy, and fault tolerance, ensuring high availability for critical network traffic.